209002161720 has 128 divisors (see below), whose sum is σ = 688364490240. Its totient is φ = 50344419840.

The previous prime is 209002161691. The next prime is 209002161743. The reversal of 209002161720 is 27161200902.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 297012 + ... + 711491.

It is an arithmetic number, because the mean of its divisors is an integer number (5377847580).

Almost surely, 2^209002161720 is an apocalyptic number.

209002161720 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

209002161720 is an abundant number, since it is smaller than the sum of its proper divisors (479362328520).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

209002161720 is a wasteful number, since it uses less digits than its factorization.

209002161720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1008685 (or 1008681 counting only the distinct ones).

The product of its (nonzero) digits is 3024, while the sum is 30.

The spelling of 209002161720 in words is "two hundred nine billion, two million, one hundred sixty-one thousand, seven hundred twenty".